title: Characterization of major depressive disorder using a multiparametric classification approach based on high resolution structural images.
abstract: BACKGROUND
  Major depressive disorder (MDD) is one of the most disabling mental illnesses. Previous neuroanatomical studies of MDD have revealed regional alterations in grey matter volume and density. However, owing to the heterogeneous symptomatology and complex etiology, MDD is likely to be associated with multiple morphometric alterations in brain structure. We sought to distinguish first-episode, medication-naive, adult patients with MDD from healthy controls and characterize neuroanatomical differences between the groups using a multiparameter classification approach.
  
  
  METHODS
  We recruited medication-naive patients with first-episode depression and healthy controls matched for age, sex, handedness and years of education. High-resolution T1-weighted images were used to extract 7 morphometric parameters, including both volumetric and geometric features, based on the surface data of the entire cerebral cortex. These parameters were used to compare patients and controls using multivariate support vector machine, and the regions that informed the discrimination between the 2 groups were identified based on maximal classification weights.
  
  
  RESULTS
  Thirty-two patients and 32 controls participated in the study. Both volumetric and geometric parameters could discriminate patients with MDD from healthy controls, with cortical thickness in the right hemisphere providing the greatest accuracy (78%, p ≤ 0.001). This discrimination was informed by a bilateral network comprising mainly frontal, temporal and parietal regions.
  
  
  CONCLUSIONS
  The sample size was relatively small and our results were based on first-episode, medication-naive patients.
  
  
  CONCLUSIONS
  Our investigation demonstrates that multiple cortical features are affected in medication-naive patients with first-episode MDD. These findings extend the current understanding of the neuropathological underpinnings of MDD and provide preliminary support for the use of neuroanatomical scans in the early detection of MDD.
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, and Department of Radiology, The Second People's Hospital of Yibin, Yibin, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Qiu
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Huang
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Junran
authors.initials: J
authors.lastname: Zhang
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, and the department of Psychiatry, State Key Lab of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Kuang
authors.affiliation: The Department of Psychiatry, State Key Lab of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: The Department of Psychiatry, State Key Lab of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.affiliation: The Department of Psychiatry, State Key Lab of Biotherapy, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Yang
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Su
authors.initials: S
authors.lastname: Lui
authors.affiliation: The Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mechelli
authors.affiliation: The Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Gong
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000473:pathology*; D003865:Major Depressive Disorder / Q000473:pathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D060388:Support Vector Machine